阅读说明：本技术 香槟色调的金属效应颜料 (Champagne-toned metallic effect pigments ) 是由 伊冯娜·宾德尔 阿达贝尔特·胡贝尔 丹尼尔·格拉泽尔 于 2019-07-25 设计创作，主要内容包括：本发明涉及金属效应颜料,其具有高遮盖力和薄氧化铁涂层,以产生香槟色调。(The present invention relates to metallic effect pigments having high hiding power and thin iron oxide coatings to produce champagne shades.)

1. Metallic effect pigment based on coated aluminum substrate flakes, wherein the aluminum substrate flakes have a thickness of 5 to 35nm, have a monolithic structure and are coated with less than 10nm of Al₂O₃The aluminum substrate sheets are surrounded by a natural passivation layer, and the aluminum substrate sheets are covered by at least one layer of SiO with the thickness of 10-100 nm₂Coating A wrapping, also applied Fe₂O₃Coating B, wrapping with SiO₂The base sheet of the coating A has a layer thickness of 5-45 nm, and is characterized in that the delta E45 is less than or equal to 3 when the pigmentation is not more than 7%, particularly, the delta E45 is less than or equal to 1 when the pigmentation is less than 7%, and the saturation (S)_uv) Has a hue angle (h) of 0.2 to 0.3_uv) The value of (A) is 50-65, the value of the flop/Alman index is more than 26, and the value of Gdiff (particle size) is not more than 6.

2. The metallic effect pigment of claim 1, wherein the aluminum substrate flakes have a thickness of 15 to 25 nm.

3. Metallic effect pigment according to claim 1 or 2, characterized in that SiO₂The thickness of the coating A is 20-80 nm.

4. Metallic effect pigment according to any of claims 1-3, characterised in that Fe₂O₃The thickness of the coating B is 10-45 nm.

5. The metallic effect pigment of any one of claims 1 to 4, wherein the iron oxide layer is a mixed layer comprising one or both ofA metal oxide in an amount of more than 0 to 20 wt% based on the layer B, and the metal oxide is selected from Al₂O₃Or TiO₂。

6. The metallic effect pigment according to any one of claims 1 to 5, further comprising an outer layer C, more particularly SiO 1 to 30nm thick, surrounding the coating B in sequence₂Layer which optionally also permeates the underlying Fe₂O₃。

7. The metallic effect pigment according to any one of claims 1 to 6, characterized in that the layer B or the layer C, if present, is subjected to an organic or organic-inorganic surface modification.

8. A process for preparing a metallic effect pigment according to any one of claims 1 to 5, comprising sol-gel processing of SiO₂Layer A is applied wet-chemically to a previously provided aluminum substrate foil, followed by the application of Fe by wet-chemical precipitation of one or more iron (III) salts₂O₃Layer B, and subsequent calcination.

9. The method according to claim 8, further comprising applying a further outer layer C, more particularly SiO 1-30 nm thick, successively surrounding the coating B₂Layer which optionally also permeates the underlying Fe₂O₃。

10. The method of claim 8 or 9, further comprising organic or organic-inorganic surface modification of the layer B or the layer C, if present.

11. Use of metallic effect pigments according to any of claims 1 to 7 in pigmented coatings, printing inks, liquid inks, plastics, glass, ceramic and decorative cosmetic formulations, in particular in nail varnishes, lip colors, eye shadows, lipsticks, shampoos and/or powders, wherein the metallic effect pigments can be used alone or in admixture with organic and/or inorganic pigments.

Technical Field

The invention relates to metallic effect pigments having a high hiding power and a thin iron oxide layer to produce champagne shades.

Background

Hitherto, there has been no known similar metallic effect pigment or pearlescent pigment having high hiding power and a yellowish-beige hue having a hue angle (h)_uv) In the range of 50 to 65 (champagne hue) and saturation (S)_uv) The range of (A) is 0.2-0.3 (the angle is less than or equal to 3 for delta E45 degrees). Pigments having similar hues are currently on the market (e.g., Eckart corporationOr Iriodin 9602 from Merck) are sometimes unsatisfactory and/or have significantly deviating hue and color saturation values.

EP2999752B1 discloses a metallic effect pigment based on thin Al substrate flakes from the VMP process, which has a high hiding power and is present in Fe₂O₃As a colored layer. WO2013/175339 discloses an aluminum-based metallic effect pigment having at least one metal oxide layer. EP2303969B1 discloses the production of effect pigments of iron-aluminum mixtures. WO 2015/040537a1 discloses a non-magnetizable effect pigment consisting of an aluminum or aluminum alloy core with one or more passivation layers and an aluminum-doped iron oxide layer. WO2007/093334a1 discloses a method for producing colour effect pigments and their use in cosmetics. These colored effect pigments consist of pigments consisting of an aluminum-containing core surrounded by a colored layer, which is produced by wet-chemical (wet-chemical) oxidation of the Al core, and/or of effect pigments having at least one metal oxide layer, which comprises at least one coloring pigment. CA2,496,126 discloses effect pigments based on metals (silver, gold, copper, aluminum, zinc, titanium and alloys thereof) for cosmetic use, which are coated with a further metal oxide layer in a wet-chemical process by means of a sol-gel process. US7,828,890B2 discloses an effect pigment having a core of aluminum or aluminum alloy, and a layer containing aluminum oxide or coating around the core of aluminum or aluminum alloyA layer containing an aluminium oxide/hydroxide, obtainable by wet-chemical oxidation of a flake-form aluminium or aluminium alloy pigment, wherein the content of metallic aluminium in the aluminium or aluminium alloy core does not exceed 90 wt.% (based on the total weight of the pigment), the oxidised aluminium or aluminium alloy pigment having at least one high refractive index (refractive index)>1.95) formed between a metal chalcogenide layer having a high refractive index and a layer (mixed layer) covering an alumina or an alumina/hydroxide. EP0950693a1 discloses a multilayer pearlescent pigment based on a non-metallic substrate. WO2011/085780a1 discloses a multilayer effect pigment based on a non-metallic substrate. WO96/22336A1 discloses coloured pigments based on flake-form aluminum substrates which are coated with a metal oxide layer having a colouring pigment therein. The "metallic effect pigments" of the professional book (second revised edition, authors: Peter Weisilin et al, Wenshenz Press) in the third chapter "colour aluminum pigments" (pages 70-76) of the "Special aluminum pigments" section, the "champagne" appearance is described) The production of the alumina pigments and their use in combination with coloring pigments. Similarly, DE19520312B4 discloses the production of color effect pigments by wet chemical oxidation of aluminum flakes.

EP3345974a1 and EP3081601a1 do describe metallic effect pigments or pearlescent pigments, but do not describe those of yellowish-beige hue whose hue angle (hue angle) (h)_uv) In the range of 50 to 65 (champagne hue) and saturation (S)_uv) The range of (A) is 0.2-0.3 (the angle is less than or equal to 3 for delta E45 degrees).

Disclosure of Invention

It is therefore an object of the present invention to provide a metallic effect pigment having a high hiding power and a yellowish-beige hue having a hue angle (h)_uv) In the range of 50 to 65 (champagne hue) and saturation (S)_uv) The range of (A) is 0.2-0.3 (the angle is less than or equal to 3 for delta E45 degrees).

This object is achieved by the embodiments described in the claims.

More particularly, a metallic effect pigment based on coated aluminum substrate flakes is provided, wherein the aluminum substrate flakes have a thickness of 5 to 35nm (preferably 15 to 25nm), have a monolithic structure and are less than 10nm (typically 2 to 5, typically 2 to 3nm) of Al₂O₃The "native" passivation layer (i.e. the passivation layer produced during production, but not applied in a separate processing step) is surrounded by at least one layer of SiO with a layer thickness of 10-100 nm (preferably 20-80 nm)₂Coating A wraps and supports a layer of additional applied Fe₂O₃Coating B which is coated with SiO₂The base sheet of the coating A has a layer thickness of 5 to 45nm (preferably 10 to 45nm, more preferably 20 to 45nm, particularly preferably 20 to 40nm), and is characterized in that the degree of Δ E45 is not more than 3 when the pigmentation (pigmentation) is not more than 7%, particularly, the degree of Δ E45 is not more than 1 when the pigmentation is less than 7%, and the degree of saturation (S) is not more than 1_uv) Has a hue angle (h) of 0.2 to 0.3_uv) The value of (A) is 50-65, the value of the flop/Alman index is more than 26, and the value of Gdiff (particle size) is not more than 6.

Optionally, an outer layer C sequentially wrapping the coating B, such as SiO 1-30 nm thick₂Layer which also optionally penetrates (percolates) the underlying Fe₂O₃. In addition, layer B or layer C (if present) may be subjected to organic or organic-inorganic surface modification.

SiO that can be considered as the actual passivation layer₂Layer a is applied wet-chemically (wet-chemically) by means of a sol-gel process. Layer B is made of Fe applied wet-chemically by a precipitation reaction₂O₃The composition has a layer thickness of 5 to 45nm, preferably 10 to 45nm, more preferably 20 to 45nm, and still more particularly 20 to 40 nm. The iron oxide layer may be a mixed layer containing one or two kinds selected from Al₂O₃Or TiO₂Based on layer B, in an amount of more than 0 to 20 wt%.

The aluminum substrate flakes are polycrystalline and have an average thickness of 5 to 35nm, preferably 15 to 25 nm. Preferably, each base sheet has a very uniform thickness. However, due to the production process, there may be fluctuations in thickness within the sheet. These fluctuations should preferably be not more than ± 25%, more preferably at most ± 10%, based on the average thickness of the flake in question. The average thickness here means the numerical average of the maximum and minimum thicknesses. The minimum and maximum layer thicknesses are determined by measurements based on transmission and scanning electron micrographs (TEM and SEM) of the coated substrate flakes.

The aluminum flakes used are preferably those known as Vacuum Metallized Pigments (VMPs). VMP can be obtained by peeling aluminum from a metallized (metallized) film. They are distinguished by a particularly low substrate flake thickness and a particularly smooth surface with enhanced reflectivity. In the context of the present invention, platelets or sheets are those sheets having a thickness/length ratio of at least 1:100 (preferably, higher).

References herein to the "thickness" of a coating or sheet of aluminum substrate are to be understood as specifying an average thickness unless certain differences are defined at relevant points.

The aluminum substrate sheet is monolithic in construction. Although the microstructure within the base sheet may change, "monolithic" in this respect means consisting of a single, independent unit free of fractures, delaminations or inclusions. The aluminum substrate sheet is preferably homogeneous in structure (homogeneous), which means that there is no concentration gradient in the sheet. In particular, the aluminum substrate sheet is not laminar in construction (herein, "natural" Al, which is produced by the production process but is not applied in a separate process step, is not considered₂O₃Passivation layer) and no particles distributed therein. In particular, they do not have a core-shell structure, wherein the shell consists, for example, of a material suitable for the base sheet and the core consists of a different material (e.g. silicon oxide). In contrast, the more complex, non-integral structure of a portion of the substrate sheet means that the production process is more complex, time consuming and expensive.

The percentage figures in the subsequent sections should be written as wt% unless otherwise stated.

The saturation (S) of the metal effect pigments of the invention when knife-coated (covered) with Δ E45 ≦ 1_uv) Has a value of 0.2 to 0.3 and a hue angle (h)_uv) Has a flop/Alman index value of more than 26 and a Gdiff (particle size) value of not more than 6. The very good hiding power of the metallic effect pigments of the invention has proven to be practical for knife-applied hiding coatings, where a Δ E45 ≦ 1 is defined, requiring that the pigmentation be no more than 7%. In particular, the value of Δ E45 ° is lower than 3.0 for 7% pigmentation. Such shades having a corresponding hiding power and flop cannot be obtained by mixing metallic effect pigments with organic and/or inorganic pigments. Furthermore, the pigment mixing is less accurate in terms of reproduction of the tone setting (reproduction).

In contrast to pigment mixtures based on aluminum pigments, the metallic effect pigments of the invention are not flammable and therefore do not have to be classified as hazardous, for example for transport purposes.

In contrast, for example, the non-innovative example of the commercially available pigment Merck Irodin 9602 fails to achieve the Δ E45 ° hiding value described above, even at high levels of pigmentation. Even at very high 20% pigmentation (here, Δ E45 ° is 5.1), a hiding power of Δ E45 ° <3 cannot be obtained. Mathematically, a knife with Δ E45 ≦ 1 would not be expected to apply a hiding coating until the pigmentation was greater than 30%.

If a commercial pigment Iriodin 9602 with a pigmentation of 20% is mixed with the yellow pigment Helio Beit UN210 (4.5%; the initial mass of the yellow pigment, unless otherwise stated, is based on the dry mass of the pigment used), in order to simulate a champagne shade, the DeltaE 45 ℃ hiding power value of the mixture lies at the top of the range reached by the metallic effect pigments of the invention, but here it must be borne in mind that the pigmentation is significantly higher. Although such compositions do not achieve the hue angle (h) achieved by the metallic effect pigments of the present invention_uv) Or a defined flop (where the addition of a yellow paste increases hiding power but compromises flop/Alman index relative to the pure pigment), but the saturation value of the mixture is at the level of the metal effect pigments of the inventionThe range of 0.2-0.3.

It is also possible to mix the commercially available silver-atom pigment with the trade name "Alustar 10200" (pigmentation of 4%) from schlenk metal pigments with 4.5% (initial mass of yellow pigment, unless otherwise stated, based on the dry mass of the pigment used) of the commercially available yellow pigment from herriobait pigment paste (Helio Beit UN120) to obtain a shade in the range of the pigments according to the invention. In fact, the Δ E45 ° hiding power of the mixtures obtained in this way is within the range achieved for the metallic effect pigments of the invention for both. The flop and Gdiff of the mixture are likewise within the scope of the metal effect pigments of the invention. However, saturation (S)_uv) Has a value of about 0.5 and a hue angle (h)_uv) A value of about 70, the range achieved by the metallic effect pigments of the present invention cannot be obtained.

If the proportion of the yellow pigment in the above-mentioned mixture is increased from 4.5% to 10%, it is indeed possible to satisfy the hue angle (h) of the metallic effect pigment of the invention_uv) But this leads to a higher saturation which is clearly outside the range of the metallic effect pigments of the invention.

By mixing pearlescent pigments and/or metallic effect pigments with one another or by adding carbon black or dyes in such a combination, it is not possible to produce a yellowish-beige champagne shade, the hue angle (h) of which_uv) 50 to 65, saturation (S)_uv) 0.2-0.3 and has extremely high covering power. When the color tone is substantially equal, the flop is also different. Carbon black must generally be added to improve hiding power.

Other disadvantages of mixtures of silver pigments based on silver units with organic dyes (e.g. organic yellow pigments) are as follows: UV stability and temperature stability are low, requiring additional mixing procedures, and in some cases, it is necessary to add stabilizers or emulsifiers. The coloring of Al pigments with inorganic (yellow) pigments having a higher UV stability does not achieve the corresponding brightness of Al pigments having a corresponding iron oxide layer (documents on the photochemical decomposition of organic pigments: Lisha Gallady, Irania Degarno, Maria Para Coloni, Geohy Maruzu, Michael Schilin, Helland Hangham, Thomum Lener, "multiple analytical studies on the photochemical degradation of synthetic organic pigments", "dyes and pigments", Vol 123, 2015, p. 396-403).

A gold-colored aluminum pigment (pigment 21YY (Zenexo golden 21YY from Schlenk metallic pigment Co.) having a pigment structure of substrate Decame (VMP aluminum flake) with a layer thickness of-25 nm and SiO thereon with a thickness of-60 nm was prepared by mixing a gold-colored aluminum pigment (pigment 21YY is exemplarily selected) with a pigment₂Layer and finally Fe with a thickness of-100 nm₂O₃A layer, also SiO with a layer thickness of-10 nm₂Coating) with carbon black, TiO₂Or pearlescent pigments (in this example Irodin 119Polar White from Merck), nor is saturation obtained (S_uv) The desired color tone is 0.2 to 0.3. These formulations do have good hiding power and good flop, but the above-mentioned saturation (S) cannot be achieved by corresponding mixing_uv) The value is obtained.

Hiding power was determined by varying the pigmentation of the coating mixture and determining the pigmentation required to apply a hiding coating with a knife at a predetermined wet film thickness. Herein pigmentation (%) means the proportion of the mass of pure pigment to the total mass of the coating mixture in a solvent-borne nitrocellulose/polycyclohexanone/polyacrylate varnish (SC-10%). To perform this determination, at least four different colorants were applied to TQC black and white cards at a wet film thickness of 38 μm using a film-thawing (film-thawing) apparatus from Zehner, and after drying, Δ E45 ° was recorded using a Byk-mac I instrument from Byk corporation. The obtained Δ E45 ° values were curve-fitted and the pigmentation value at Δ E45 ° -1 was determined. If at a predetermined wet film thickness of 38 μm Δ E45 ≦ 1, the layer is defined as a masking layer (masking layer). The lower the pigmentation required to reach this value, the higher the hiding power.

Generally, the average maximum diameter of the flakes is about 2 to 200 μm, more particularly about 5 to 100 μm. Of the pigments of the invention₅₀(Al substrate + SiO)₂+Fe₂O₃Layer) is usually 15 to 30 μm. Unless otherwise stated, d herein₅₀Values were determined by using a Sympatec Helos instrument with a Quixel wet dispersion.

Typically, a coating of a portion of the surface of the coated substrate flake is sufficient to obtain a lustrous pigment. For example, only the upper and/or lower side of the sheet may be coated, while the sides are excluded. However, according to the invention, the entire surface (including the sides) of the optionally passivated substrate sheet is covered by the coatings a and B. Thus, the substrate web is completely surrounded by coatings a and B. This improves the optical properties of the pigments of the invention and increases the mechanical and chemical stability of the coated substrate flakes.

The method for producing a metallic lustrous pigment of the present invention comprises the steps of: providing an aluminum substrate sheet (typically a passivated aluminum substrate sheet); SiO by sol-gel process₂Layer a is applied wet-chemically to one such aluminum substrate sheet provided beforehand; subsequent application of Fe by wet-chemical precipitation of one or more iron (III) salts₂O₃A layer B; and subsequently calcined.

To produce the coating a, an organosilicon compound in which an organic group is bonded to a metal via an oxygen atom is efficiently hydrolyzed in the presence of a base sheet. A preferred example of an organosilicon compound is Tetraethylorthosilicate (TEOS). The hydrolysis is preferably carried out in the presence of a base (e.g. KOH, NaOH, Ca (OH))₂Or NH₃) Or acids such as phosphoric acid and organic acids such as acetic acid, as catalysts. Although the amount of water is preferably from 2 to 100 times, more particularly from 5 to 20 times, the water must be present in at least the stoichiometric amount required for hydrolysis. Based on the amount of water used, it is common practice to add 1 to 40 vol% (preferably 1 to 10 vol%) of an aqueous base (e.g., KOH, NaOH, Ca (OH)) having a concentration of 25 wt%₂Or NH₃). For the temperature range, it has proven advantageous to heat the reaction mixture at 40 to 80 ℃ (preferably 50 to 70 ℃) for 1 to 12 hours (preferably 2 to 8 hours).

In terms of process, the method of coating a substrate sheet with coating a is as follows:

after introducing the aluminum substrate flakes, the organic solvent, water and the catalyst, the silicon-containing compound for hydrolysis is added to the preheated reaction mixture either in pure form or in solution (e.g., at a concentration of 30 to 70 vol%, preferably 40 to 60 vol% in the organic solvent). Alternatively, the silicon-containing compound can be metered continuously at elevated temperature, in which case water and the aqueous base can be initially added, or else metered continuously. After the coating was complete, the reaction mixture was cooled back to room temperature.

To prevent agglomeration during the coating process, the suspension may be subjected to intense mechanical stress, for example by pumping, vigorous stirring or the use of ultrasound.

The coating step may optionally be repeated one or more times. If the mother liquor (motherliquor) is milky turbid in appearance (mikily cloudy), it is recommended to replace it before further application.

The aluminum substrate flakes covered with coating A can be separated in a simple manner, for example by filtration, washed with an organic solvent, preferably alcohols are also usually used as solvents, and then dried (usually at 20 to 200 ℃ for 2 to 24 hours).

Layer B may be applied by hydrolytic decomposition of iron (III) salts (e.g., iron (III) chloride) and sulfates, followed by calcination to convert the resulting hydroxide-containing layer to an oxide layer. The heating is continuously carried out (preferably at a temperature of 250-550 ℃) for 5-360 minutes, preferably at a temperature of 300-450 ℃ for 30-120 minutes.

If an iron oxide layer is used as the mixed layer, the mixed layer contains one or two metal oxides in an amount of more than 0 to 20 wt% based on the layer B, and the metal oxide is selected from Al₂O₃Or TiO₂In addition to the iron (III) salts, e.g. AlCl₃And/or TiOCl₂Can be used as Al respectively₂O₃And TiO₂A precursor compound of (1).

By means of the production method of the invention, coated substrate sheets can be reproducibly mass-produced in a simple manner. Fully encapsulated pigment particles are obtained with a high quality individual coating (uniform, thin film).

The metallic effect pigments of the invention can be used advantageously in cosmetics, provided that they are toxicologically/microbiologically acceptable. Here, a broad-spectrum (spread-spectrum) can be used: mainly nail polish, lip gloss, eye shadow and lipstick. Other possible uses include, for example, shampoos and powders.

The pigments of the invention may be mixed with organic or inorganic dyes in order to enhance the effect.

Drawings

FIG. 1 illustrates the general layer structure (not to scale) of a metallic effect pigment of the present invention;

FIG. 2 shows a SEM cross-section of a metallic effect pigment according to the invention, i.e. an inventive pigment (construction of this pigment: substrate-Decome (VMP aluminum flake) with a layer thickness of-25 nm, on which SiO is present at-60 nm₂Layer, and finally Fe of 45nm₂O₃Layer without further coating, e.g. further SiO₂Coated, and without surface modification).

Detailed Description

The following examples serve to further illustrate the invention, but are not limited thereto.

Examples

The inventive pigment Decome (VMP aluminum) is used as a substrate, and the layer A SiO₂The layer thickness is in the range of innovation, layer B ═ Fe₂O₃The layer thickness is within the scope of the innovation.

Examples of innovations

(1) Inventive pigment + about 1.6% Al₂O₃

(2) Novel pigment

(3) With about 6% TiO₂In the pigment

(4) Has about 1.6% of Al₂O₃+SiO₂Inventive pigment (layer C, arithmetic thickness 16.5nm)

(5) Has about 1.6% of Al₂O₃+SiO₂Inventive pigment (layer C, arithmetic thickness 26.5nm)

Non Innovative examples

(6) Merck Iriodin 9602 with 4.5% of yellow pigment Helio Beit UN210

(7)Merck Iriodin 9602

(8) Alustar 10200 with 4% yellow pigment Helio Beit UN210

(9) Alustar 10200 with 10% yellow pigment Helio Beit UN210

(10) Pigment 21YY (Zenexo golden shine, Schlenk Metal pigments Co.)

(11) Pigment 21YY with 1% of Helio Beit Carbon Black (Carbon Black Dispersion)

(12) Pigment 21YY with 10% of Iridin 119

(13) Pigment 21YY with 20% of Iridin 119

(14) Pigment 21YY with 50% of Iridin 119

(15) With 1.5% TiO₂Pigment 21YY of

Production of the inventive examples

First, SiO was used by a sol-gel method using tetraethyl orthosilicate (TEOS)₂Al flakes are coated (see e.g. WO2015/014484A 1).

Subsequently, a suspension with an aluminum content of 15g was added to a 2L beaker. The suspension was made up to 900 g with tap water. At the start of the synthesis, a slight acidification was carried out. FeCl addition was then started₃And (3) solution. By adding an alkaline solution (e.g., KOH, NaOH, Ca (OH)₂Or NH₃) The pH was kept constant. At the end of the synthesis, the pH rises with stirring. Subsequently, after precipitation, the resulting pigment is isolated by filtration, drying and subsequent calcination.

The following table lists the layer thickness and color data (coloristic data) for the inventive examples and non-inventive examples described above:

SEM micrographs were recorded with Zeiss Auriga 40 scanning electron microscopes, respectively.

The colorimetric data were obtained by knife coating a coating measuring the pigment (pigmentation 7%, SC-10% in solvent-borne nitrocellulose/polycyclohexanone/polyacrylate varnish unless otherwise specified) applied to DIN a5 black/white card of TQC on an automatic film-forming apparatus from Zehntner using a 38 μm wire-wound knife.

Color data was measured using Byk-mac I from Byk corporation.